STP condition mean we have P=1 atm. T=273K. R=ideal gas constant, but make sure you use the one that has the same units of pressure, temperature that you are using. In this case R=0.0821 L*atm K^-1mol^1. You are provided with n=2.1 moles.
V=nRTP
Input your values and solve.
Answer: Hydrogen that is not used in balloons because hydrogen burns very easily.
pls mark brainliest
C unbalanced force is occuring
I think it’s the first one. Electroplating means you put on a layer of metal on something.